xentrace: Remove redundant tb_done_init checks, and add missing ones.

Hand inspection of gcc -02 output confirms significantly shorter
codepaths for inactive (i.e. normal case) tracing.

Signed-off-by: Michael A Fetterman <Michael.Fetterman@cl.cam.ac.uk>

1 files changed, 30 insertions, 11 deletions

diff --git a/xen/include/asm-x86/hvm/trace.h b/xen/include/asm-x86/hvm/trace.h
index 54c578f912..04f90e0f98 100644
--- a/xen/include/asm-x86/hvm/trace.h
+++ b/xen/include/asm-x86/hvm/trace.h
@@ -37,6 +37,9 @@ static inline void hvmtrace_vmexit(struct vcpu *v,
                                    unsigned long rip,
                                    unsigned long exit_reason)
 {
+    if ( likely(!tb_init_done) )
+        return;
+
 #ifdef __x86_64__
     if(hvm_long_mode_enabled(v))
     {
@@ -50,7 +53,7 @@ static inline void hvmtrace_vmexit(struct vcpu *v,
         d.vid = v->vcpu_id;
         d.exit_reason = exit_reason;
         d.rip = rip;
-        trace_var(TRC_HVM_VMEXIT64, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
+        __trace_var(TRC_HVM_VMEXIT64, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
     } else {
 #endif
         struct {
@@ -63,7 +66,7 @@ static inline void hvmtrace_vmexit(struct vcpu *v,
         d.vid = v->vcpu_id;
         d.exit_reason = exit_reason;
         d.eip = rip;
-        trace_var(TRC_HVM_VMEXIT, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
+        __trace_var(TRC_HVM_VMEXIT, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
 #ifdef __x86_64__
     }
 #endif
@@ -75,9 +78,13 @@ static inline void hvmtrace_vmentry(struct vcpu *v)
     struct {
         unsigned did:16, vid:16;
     } d;
+
+    if ( likely(!tb_init_done) )
+        return;
+
     d.did = v->domain->domain_id;
     d.vid = v->vcpu_id;
-    trace_var(TRC_HVM_VMENTRY, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
+    __trace_var(TRC_HVM_VMENTRY, 1/*cycles*/, sizeof(d), (unsigned char *)&d);
 }
 
 static inline void hvmtrace_msr_read(struct vcpu *v, u32 ecx, u64 msr_content)
@@ -87,11 +94,15 @@ static inline void hvmtrace_msr_read(struct vcpu *v, u32 ecx, u64 msr_content)
         u32 ecx;
         u64 msr_content;
     } d;
+
+    if ( likely(!tb_init_done) )
+        return;
+
     d.did = v->domain->domain_id;
     d.vid = v->vcpu_id;
     d.ecx = ecx;
     d.msr_content = msr_content;
-    trace_var(TRC_HVM_MSR_READ, 0/*!cycles*/, sizeof(d), (unsigned char *)&d);
+    __trace_var(TRC_HVM_MSR_READ, 0/*!cycles*/, sizeof(d), (unsigned char *)&d);
 }
 
 static inline void hvmtrace_msr_write(struct vcpu *v, u32 ecx, u64 msr_content)
@@ -101,16 +112,23 @@ static inline void hvmtrace_msr_write(struct vcpu *v, u32 ecx, u64 msr_content)
         u32 ecx;
         u64 msr_content;
     } d;
+
+    if ( likely(!tb_init_done) )
+        return;
+
     d.did = v->domain->domain_id;
     d.vid = v->vcpu_id;
     d.ecx = ecx;
     d.msr_content = msr_content;
-    trace_var(TRC_HVM_MSR_WRITE, 0/*!cycles*/,sizeof(d), (unsigned char *)&d);
+    __trace_var(TRC_HVM_MSR_WRITE, 0/*!cycles*/,sizeof(d), (unsigned char *)&d);
 }
 
 static inline void hvmtrace_pf_xen(struct vcpu *v, unsigned long va,
                                    u32 error_code)
 {
+    if ( likely(!tb_init_done) )
+        return;
+
 #ifdef __x86_64__
     if(hvm_long_mode_enabled(v))
     {
@@ -123,8 +141,8 @@ static inline void hvmtrace_pf_xen(struct vcpu *v, unsigned long va,
         d.vid = v->vcpu_id;
         d.error_code = error_code;
         d.va = va;
-        trace_var(TRC_HVM_PF_XEN64, 0/*!cycles*/,sizeof(d),
-                  (unsigned char *)&d);
+        __trace_var(TRC_HVM_PF_XEN64, 0/*!cycles*/,sizeof(d),
+                    (unsigned char *)&d);
     } else {
 #endif
         struct {
@@ -136,7 +154,8 @@ static inline void hvmtrace_pf_xen(struct vcpu *v, unsigned long va,
         d.vid = v->vcpu_id;
         d.error_code = error_code;
         d.va = va;
-        trace_var(TRC_HVM_PF_XEN, 0/*!cycles*/,sizeof(d), (unsigned char *)&d);
+        __trace_var(TRC_HVM_PF_XEN, 0/*!cycles*/,sizeof(d),
+                    (unsigned char *)&d);
 #ifdef __x86_64__
     }
 #endif
@@ -144,7 +163,7 @@ static inline void hvmtrace_pf_xen(struct vcpu *v, unsigned long va,
 
 #define HVMTRACE_ND(evt, vcpu, count, d1, d2, d3, d4)                   \
     do {                                                                \
-        if (DO_TRC_HVM_ ## evt)                                         \
+        if ( unlikely(tb_init_done) && DO_TRC_HVM_ ## evt )             \
         {                                                               \
             struct {                                                    \
                 unsigned did:16, vid:16;                                \
@@ -156,8 +175,8 @@ static inline void hvmtrace_pf_xen(struct vcpu *v, unsigned long va,
             _d.d[1]=(d2);                                               \
             _d.d[2]=(d3);                                               \
             _d.d[3]=(d4);                                               \
-            trace_var(TRC_HVM_ ## evt, 0/*!cycles*/,                    \
-                      sizeof(u32)*count+1, (unsigned char *)&_d);       \
+            __trace_var(TRC_HVM_ ## evt, 0/*!cycles*/,                  \
+                        sizeof(u32)*count+1, (unsigned char *)&_d);     \
         }                                                               \
     } while(0)